阅读说明：本技术 一种直升机座舱地板可调频率动力吸振器 (Frequency-adjustable dynamic vibration absorber for helicopter cabin floor ) 是由 于仁业 孙秀文 李宗秀 王金亮 乔文慧 夏发令 于 2019-09-29 设计创作，主要内容包括：本发明属于直升机减振技术,涉及一种直升机动力吸振器减振装置。所述的吸振器包括上支撑板(1)和下支撑板(2),上支撑板(1)和下支撑板(2)一端固定,上支撑板(1)的另一端固定在直升机座舱地板,下支撑板(2)的另一端固定有质量块,呈悬空状态。本发明的动力吸振器结构体积小、简单、易于安装,但可以产生较大的反共振载荷,具有较好的减振效果；并且减振结构具有无限寿命,安全可靠。动力吸振器安装于地板下方工作时不对扰驾驶员产生干扰,也不会于其它操纵和系统结构产生干涉,与直升机具有很好的适应性。(The invention belongs to the helicopter vibration reduction technology, and relates to a vibration reduction device of a helicopter dynamic vibration absorber. The vibration absorber comprises an upper supporting plate (1) and a lower supporting plate (2), wherein one end of the upper supporting plate (1) and one end of the lower supporting plate (2) are fixed, the other end of the upper supporting plate (1) is fixed on the floor of a cabin of the helicopter, and the other end of the lower supporting plate (2) is fixed with a mass block which is in a suspended state. The dynamic vibration absorber has the advantages of small structure volume, simplicity and easy installation, but can generate larger anti-resonance load and has better vibration attenuation effect; and the damping structure has infinite life, safety and reliability. When the dynamic vibration absorber is arranged below the floor and works, the dynamic vibration absorber does not interfere with a driver, does not interfere with other control and system structures, and has good adaptability to a helicopter.)

1. A helicopter cabin floor adjustable frequency dynamic vibration absorber is characterized in that: the vibration absorber comprises an upper supporting plate (1) and a lower supporting plate (2), wherein one end of the upper supporting plate (1) and one end of the lower supporting plate (2) are fixed, the other end of the upper supporting plate (1) is fixed on the floor of a cabin of the helicopter, and the other end of the lower supporting plate (2) is fixed with a mass block which is in a suspended state.

2. The helicopter cabin floor adjustable frequency dynamic vibration absorber of claim 1, wherein: go up backup pad (1) and/or bottom suspension fagging (2) be provided with and buckle, go up and form the space of moving from top to bottom between backup pad (1) and bottom suspension fagging (2).

3. The helicopter cabin floor adjustable frequency dynamic vibration absorber of claim 1, wherein: the upper supporting plate (1) is provided with downward bending.

4. The helicopter cabin floor adjustable frequency dynamic vibration absorber of claim 1, wherein: the mass block is a lead block (6).

5. The helicopter cabin floor adjustable frequency dynamic vibration absorber of claim 1, wherein: the mass block comprises a plurality of mass block units with different masses.

6. The helicopter cabin floor adjustable frequency dynamic vibration absorber of claim 1, wherein: the mounting centers of the upper supporting plate (1) and the cabin floor and the gravity center of the mass block are positioned on the same vertical line.

7. The helicopter cabin floor adjustable frequency dynamic vibration absorber of claim 1, wherein: the vibration absorber is installed on the floor of the helicopter cabin along the course.

8. The helicopter cabin floor adjustable frequency dynamic vibration absorber of claim 1, wherein: the vibration absorber is arranged below the floor of the cabin of the helicopter.

Technical Field

The invention belongs to the helicopter vibration reduction technology, and relates to a vibration reduction device of a helicopter dynamic vibration absorber.

Background

The helicopter is subjected to periodic vibration load in the flying process, and the serious vibration problem of the helicopter is formed. The large vibration not only causes the reduction of the fatigue life of the structure, but also causes the uncomfortable feeling and the easy fatigue of the driver, and influences the flight safety. In order to reduce the vibration level of the helicopter, a helicopter vibration reduction technology can be adopted. Helicopter vibration damping technology can be divided into two aspects of passive type and active type. The passive vibration reduction technology refers to vibration reduction measures without energy input from the outside, such as a dynamic vibration absorber consisting of springs and mass elements. The active vibration reduction technology requires energy input from the outside to maintain the normal operation of the actuating mechanism, such as active vibration isolation. For the problem that the floor of the cockpit of the helicopter in the test flight stage or delivered to a user has large vibration, the active vibration reduction technology cannot be adopted to reduce the vibration of the floor of the cockpit from the consideration of technical and economic factors, and only the passive vibration reduction technology can be adopted. The frequency-adjustable dynamic vibration absorber is good in vibration reduction effect, exquisite and simple in structure, easy to install and adjustable in vibration reduction frequency, and becomes a preferred scheme for solving the problem of large floor vibration of a cabin of a helicopter.

Disclosure of Invention

The technical problems solved by the invention are as follows: the dynamic vibration absorber suitable for the helicopter is good in vibration reduction effect, small in size, simple in structure and easy to install and adjust, and solves the technical problem that the floor of the helicopter vibrates greatly in the prior art.

The technical scheme of the invention is as follows: the utility model provides an adjustable frequency dynamic vibration absorber in helicopter cabin floor, the bump leveller include backup pad 1 and bottom suspension fagging 2, go up backup pad 1 and 2 one ends of bottom suspension fagging and fix, the other end of going up backup pad 1 is fixed on helicopter cabin floor, the other end of bottom suspension fagging 2 is fixed with the quality piece, is unsettled state. The dynamic vibration absorber has the advantages of small structure volume, simplicity and easy installation, but can generate larger anti-resonance load and has better vibration attenuation effect; and the damping structure has infinite life, safety and reliability. When the dynamic vibration absorber is arranged below the floor and works, the dynamic vibration absorber does not interfere with a driver, does not interfere with other control and system structures, and has good adaptability to a helicopter.

Preferably, the upper supporting plate 1 and/or the lower supporting plate 2 are/is provided with a bend, and an up-and-down movement space is formed between the upper supporting plate 1 and the lower supporting plate 2. This design has avoided the quality piece to produce big vertical displacement and bump with floor structure when resonating through providing the up-and-down motion space of upper support plate 1, bottom suspension fagging 2.

Preferably, the upper supporting plate 1 is provided with a downward bend, so that a motion space is formed between the supporting plate and a floor mounting plane, and the supporting plate 1 is prevented from being driven by the mass block to generate vertical displacement when being resonated to collide with a floor structure.

Preferably, the mass block is a lead block 6. The driver has more control rod systems and system equipment for pedaling the lower part of the cabin floor, and the redundant space is limited. In order to generate a large anti-resonance load and obtain a good vibration damping effect, it is necessary that the mass has a large mass, and when the volume of the mass is spatially limited, the mass M increases as the density ρ increases, as can be seen from M ═ ρ V. Among three common aviation metal materials, aluminum, steel and lead, the lead has the highest density, so that the mass block material is lead. The large-mass lead block enables the dynamic vibration absorber to play a vibration damping role to the maximum extent in a limited space.

Preferably, the mass block comprises a plurality of mass block units with different masses. In order to make the dynamic vibration absorber perform the vibration damping function, the natural frequency of the dynamic vibration absorber must be adjusted to be consistent with the main vibration excitation frequency of the helicopter. The frequency of the dynamic vibration absorber depends on the mass and the rigidity, after the designed dynamic vibration absorber is manufactured and installed on a helicopter structure, due to errors of manufacturing and boundary conditions, the natural frequency of the dynamic vibration absorber is not completely consistent with the excitation frequency of the helicopter, and a plurality of mass block units with different masses need to be designed at the moment, so that the natural frequency of the dynamic vibration absorber can be adjusted by adjusting the quantity of the installed mass blocks on site.

Preferably, the mounting centers of the upper support plate 1 and the cabin floor are located on the same vertical line as the center of gravity of the mass block. When the mass block vibrates, the vibration load on the mass block is mainly in the vertical direction, so that the acting force direction of the vibration load can pass through the installation center of the cabin floor, and the vibration load can hardly generate acting moment on the upper supporting plate 1 and the cabin floor, so that the vibration stress of the supporting plate 1 and the cabin floor is reduced, the power vibration absorber can be easily designed to have infinite service life, and the reliability is higher.

Preferably, the vibration absorber is mounted on the floor of the cockpit of the helicopter in heading direction. The cabin floor vibration of helicopter driver pedal department is big, makes the driver feel difficult, easy tired, influences flight safety, and consequently the dynamic vibration absorber is installed in driver department cabin floor pedal position department, can reduce the vibration level of mounted position department, and isolated vibration is to driver's transmission.

Preferably, the vibration absorber is mounted below the floor of the cockpit of the helicopter. Because the pedal position on the cockpit floor belongs to the foot moving range of the driver, the dynamic vibration absorber is arranged below the floor, and the operation action of the driver can be prevented from being interfered.

Drawings

Fig. 1 is a sectional view showing the installation of the dynamic vibration absorber according to the present invention.

Detailed Description

The technical scheme of the invention designs the dynamic vibration absorber with a new structure form, and the structure has small volume and is easy to install; the dynamic vibration absorber with the structural form realizes the variable natural frequency of the dynamic vibration absorber by adjusting the mass of the counterweight, and meets the vibration reduction requirements of helicopters of different models; the connecting structure of the counterweight mass block is ingenious in design and small in vibration stress, and the specific structure is described as follows:

the technical scheme of the invention comprises an upper support plate, a lower support plate, a reinforcing plate and lead block units with different qualities. Wherein, the upper supporting plate is a rectangular flat plate with two metal plates bent to form an inner obtuse angle and an outer obtuse angle, and the lower supporting plate is a rectangular flat plate, and the two supporting plates form a right trapezoid shape. Different quality lead block units adopt bolted connection with the bottom suspension fagging, and upper and lower bottom suspension fagging adopts bolted connection in right trapezoid hypotenuse department and reinforcing plate, and the upper supporting plate can adopt bolted connection with damping position structure above right trapezoid. The frequency of the dynamic vibration absorber can be adjusted by adjusting the quantity of the lead block units with different masses to enable the dynamic vibration absorber to reach a resonance state, so that the vibration absorbing function is exerted, and the vibration at the connecting structure is reduced.

When the method is implemented specifically, a position area with the maximum vibration is determined as an installation position area of the dynamic vibration absorber according to a floor vibration test result, and the installation position is finally determined by combining available space at the lower part of the floor. The installation and debugging steps are as follows:

1. 4 mounting holes are prefabricated at the mounting position of the floor, and the support plate 1 is connected with the floor of the cabin through 4 bolts 8.

2. A preliminarily estimated number of lead mass adjusting units (6, 7) are connected to the lower support plate 2 by bolts 10.

3. And (3) connecting the lower support plate 2 connected in the step (2) with the upper support plate 1 connected to the floor in the step (1) and the reinforcing plates (4 and 5) through bolts 9, so that the dynamic vibration absorber is installed, and then performing a frequency debugging test.

4. And adhering an acceleration sensor on the mounted mass block of the dynamic vibration absorber, performing frequency sweep vibration excitation on the helicopter in a ground state, measuring the natural frequency of the dynamic vibration absorber, and adjusting the frequency of the dynamic vibration absorber according to the measurement result.

5. If the measured natural frequency of the dynamic vibration absorber is greater than the first-order excitation frequency of the helicopter rotor, returning to the step 2, increasing the number of the lead block quality units (6 and 7), and performing the measurement experiment of the step 4 again; if the measured natural frequency of the dynamic vibration absorber is smaller than the first-order excitation frequency of the helicopter rotor, returning to the step 2, reducing the number of lead block quality units (6 and 7), and carrying out the measurement experiment of the step 4 again; and if the measured natural frequency of the dynamic vibration absorber is equal to the first-order excitation frequency of the helicopter rotor, finishing the frequency adjustment test of the dynamic vibration absorber.

6. And carrying out test flight verification.